A machine for social infrastructure such as a power generation gas turbine is required to operate 24 hours a day. In order to maintain high availability of such a machine, it is necessary to prevent unplanned outages. For that purpose, it is necessary to change a maintenance method from a periodic maintenance based on an operating time of the machine of the related art to a state monitoring and maintenance that appropriately performs preventive maintenance based on a state of the machine.
In order to realize the state monitoring and maintenance, a role of a machine diagnostic apparatus, which analyzes sensor data collected via various sensors provided in the machine in accordance with a predetermined abnormality diagnosis procedure and diagnoses prediction of abnormality or failure of the machine, is important. Here, the abnormality diagnosis procedure refers to a processing flow of a computer that processes data acquired from one or more sensors and diagnoses the prediction of abnormality of the machine based on the processing result.
Normally, the machine subjected to such diagnosis has a plurality of operation modes. Generally, sensor values that are obtained from sensors provided in the machine are different for each operation mode. Therefore, in the abnormality diagnosis procedure of the machine diagnostic apparatus, it is inevitable to consider the operation mode of the machine. That is, the abnormality diagnosis procedure that does not take into consideration the operation mode of the machine leads to a false report or a report failure of a diagnosis result. Moreover, the false report is a case where a normal state of the machine is diagnosed as abnormal and the report failure is a case where an abnormal state of the machine is diagnosed as normal.
Therefore, even in the machine diagnostic apparatus of the related art, the operation mode of the machine is taken into consideration. For example, in PTL 1, as a precedent example of the machine diagnostic apparatus in consideration of the operation mode, a facility diagnostic apparatus is disclosed in which “each of differences in an operation state of each device configuring a facility including a plurality of devices provided within one room or the like is regarded as a difference of all the operation modes, reference data of an inverse filter or the like is obtained for each operation mode, and in the determination of the presence or absence of abnormality, the determination of the presence or absence of abnormality is performed based on a signal obtained at that time and the reference data that is obtained for the same operation mode as the operation mode at that time” is disclosed.